net/nfp: add NSP symbol resolution command

net/nfp: add NSP symbol resolution command

Firmware has symbols helping to configure things like number of
PF ports, vNIC BARs addresses inside NFP memories, or ethernet
link state. Different firmware apps have different things to map
and likely different internal NFP addresses to use.

Host drivers can use the NSPU interface for getting symbol data
regarding different hardware configurations. Once the driver has
the information about a specific object, a mapping is required
configuring an NFP expansion bar creating a device PCI bar window.

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>